I. Field of the Invention
The present invention relates generally to valves for controlling fluid flow that operate to permit and disrupt fluid flow automatically, and particularly to ring-type valve structures, including biasing means, used as air inlet valves and exhaust valves in high pressure gas compressors and fluid pumps.
II. Description of the Prior Art
Ring-type valves per se are generally well known in the prior art, and have a wide acceptance in use for air compressors and pumps. Basically, these ring-type valves are opened and closed by pressure differential on opposite sides of the ring valve. It is also heretofore known to include biasinq of spring devices along with such ring valves in order to accurately control valve movement upon a pressure differential which is above the spring force of the spring selected in each case. In this way, the valve is opened or closed only upon reaching a predetermined pressure differential dependent on the spring properties of the spring chosen, and the mass of the valve, wherein the valve action can be predicted.
Examples of ring valves and spring devices are shown by Herzmark, U.S. Pat. No. 2,382,716, issued Aug. 14, 1915; Peters, U.S. Pat. No. 1,222,321, issued April 10, 1917; and Garland, U.S. Pat. No. 3,786,834, issued Jan. 22, 1974.
The Herzmark reference is directed to an air compressor which utilizes ring valves to control air flow between low stage and high stage air compression cylinders. Herzmark also discloses the use of spring washers that are freely supported to bias the ring valves in a desired position. This type of spring washer and ring valve requires additional supporting structure to retain the spring washer that decreases the efficiency of the air compressor by lowering the compression volume of each cylinder at the end of the suction stroke, and increases the cost, weight and complexity of the valve assembly.
The above-mentioned patents to Peters and Garland simply illustrate the conventional use of ring valves and spring devices arranged on air compressors concentrically. These references are likewise deficient in that additional support structure is needed for the valves and springs.